1. Field of the Invention
The present invention relates to a gas-aerosol filter for chemical/biological protective mask and methods for use and, more particularly, to a plastic type of canister system which houses carbon beads attached to a reticulated foam and an electrostatically charged aerosol/particulate filter.
2. Brief Description of the Prior Art
It is desirable that respiratory devices designed for military use have low profiles, be resistant to having faceseals broken during operational conditions and have relatively low airflow resistance. The United States Army's M17 chemical/biological protective mask uses a dual filter system which has the filters mounted on the cheeks of the respiratory protective device. While this mask design afforded a low profile, it was abandoned during the development of the M40 protective mask in order to provide a canister type system which is NATO compatible and provides a higher level of vapor protection.
The standard canister used with the M40 chemical/biological protective mask has an airflow resistance of approximately 45 mm of water at an airflow rate of 85 liters per minute. Limitations in technology and threat requirements have prevented further reductions in resistances. Reductions in these resistances are desirable since it is found that higher resistances increase physiological burden at higher work rates.